Double faults happen when a fault occurs while entering a faulthandler.

They're extremely rare in the field. In my experience, they only occurwhen you've got hardware troubles or are hacking on the fault handlingcode. They're rare enough that I showed one to akpm a few months backand he claimed he'd never seen one before.

If a fault occurs while trying to invoke the double fault handler(perhaps because you don't have one), you get a triple fault whichcauses a reboot.

> Trying to figure out when it would be worth using this...

Typical usage for this and similar options is in boxes that have nouseful logging or diagnostic facilities.